Definition of touchpad in English:

noun

You should spend a few minutes using a laptop with a touch pad before you make up your mind, but if your thumbs tend to drift around below the space bar, you may find your mouse pointer bouncing around when you least expect it.

A controller is operable with the touch pad for receiving a signal from the touch pad in response to an operator touching the touch pad.

The round touch pad used to scroll through song lists now sports the stop/start, fast forward, reverse and menu buttons that were placed between the screen and this wheel.